“Run, hide, fight” is standard protocol for active shooter situations. It means: Run, evacuate if possible; Hide, get silently out of view; or Fight, as a last resort, take action to disrupt or incapacitate the shooter if your life is in imminent danger.

The university followed up with another tweet: “Continue to shelter in place in north campus area. Follow directions of Police on scene.” The university asked for anyone with information to call police.

The Columbus Police Department referred calls to Ohio State. A dispatcher for Ohio State police declined to comment. The media relations office said it wasn’t immediately able to comment.

Many police vehicles were at the scene. No other information was immediately available.

With nearly 60,000 students at its main Columbus campus, Ohio State is one of the nation’s largest universities.